This invention relates to a latch. More particularly the latch is intended for use with a window sash which is sliding mounted with a window frame.
Latch devices for latching a sliding window sash in the closed position are known. However, there are drawbacks or shortcomings in many of the known latch devices. In these more security conscious times previously known latch devices may not provide the level of security required nowadays.
For example, a security issue arises if a latch device can be disengaged and remain so in the event that the window sash is not moved from the closed position. As a result the window sash may appear to be latched closed but in reality is unlatched. Therefore unauthorised entry through the window can occur.
Another situation which can occur with many known latching devices is that upon the window sash being moved into a closed position the latching device needs to be manually manipulated in order to achieve latching. There are, however, known latching devices which automatically relatch upon the sash moving to the closed position. These rely on some mechanical triggering between a moving element (rail) of the sash and fixed element (rail) of the window frame. Thus, if the mechanical triggering does not occur or fully trigger the relatching, the sash is closed but not latched. Thus the security issue mentioned above once again exists.